Strypi is a family of US re-entry vehicle test boosters, anti-missile targets and sounding rockets. They use a Castor first stage with two Recruit strap-on boosters, plus a range of upper stages.[1] It is 31 inches (79 centimeters) in diameter, and has a maximum flight height of 124 miles (200 kilometers).
It was originally designed and built in 1962 by teams from the Sandia National Laboratories in an around-the-clock program that was a part of a larger nuclear weapons testing program, undertaken prior to the imposition of the Limited Test Ban Treaty (LTBT) in October, 1963. It was designed to take a nuclear warhead into space for extra-atmospheric testing. Though it performed this function only once, in Test Checkmate of Operation Fishbowl, it became the "workhorse" of Sandia's rocket research program.[2] The rocket's name came from the efforts of the Sandia teams, which had "taken the tiger by the tail".[2]
In 1968, a modified Strypi was used in Material Test Vehicle (MTV) booster tests. Although atmospheric nuclear testing was now banned, as a part of the Test Readiness Program the U.S. Air Force continued to develop the means of testing, should the ban be lifted.[2]
Several versions of Strypi were developed, maintaining the original Recruit and Castor first and second stages or adding a third stage.[3][1]
| Version | First Launch | Last Launch | Flights | Booster | Stage 1 | Stage 2 | Stage 3 |
|---|---|---|---|---|---|---|---|
| Strypi Antares | 1962-07-09 | 1962-10-20 | 7 | 2 × Recruit | Castor-1 | - | - |
| Strypi-2 | 1979-11-13 | 1 | 2 × Recruit | Castor-1 | - | - | |
| Strypi-2R | 1974-11-03 | 1 | 2 × Recruit | Castor-1 | - | - | |
| Strypi-2AR | 1974-02-07 | 1 | 2 × Recruit | Castor-2 | - | - | |
| Strypi-4 | 1966-09-01 | 1 | 2 × Recruit | Castor-1 | Star-26 | - | |
| Strypi-4A | 1974-03-23 | 1 | 2 × Recruit | Castor-1 | Star-26 | - | |
| Strypi-4R | 1976-06-07 | 1 | 2 × Recruit | Castor-1 | Star-26 | - | |
| Strypi-6 | 1968-11-01 | 1970-06-01 | 3 | 2 × Recruit | Castor-1 | ? | ? |
| Strypi-7R | 1975-03-11 | 1975-09-18 | 2 | 2 × Recruit | Castor-1 | Alcor-1B | Alcyone IA BE-3 |
| Strypi-7AR | 1972-10-15 | 1974-10-01 | 2 | 2 × Recruit | Castor-2 | Alcor | Alcyone IA BE-3 |
| Strypi-9 | 1995-06-26 | 1995-06-29 | 2 | 2 × Recruit | Castor-1 | Antares-2A | - |
| Strypi-11 | 1987-01-01 | 1991-02-18 | 4 | 2 × Recruit | Castor-1 | Antares-2A | Star-27 |
| Strypi-12R | 1997-02-10 | 1997-10-04 | 2 | 2 × Recruit | Castor-1 | Orbus-1 | - |
| Strypi Tomahawk | 2 × Recruit | Castor-1 | ? | Tomahawk | |||
The SPARK, also known as the Super Strypi, is a three-stage derivative of the Strypi powerful enough to place a 250 kg payload into Sun-synchronous orbit. The Super Strypi was first launched on 3 November 2015, although on that test the first stage failed soon after lift-off.[4]
